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AES Cipher - Military-Grade Encryption Tool

Publicado el 22 de octubre de 2025

AES Encryption Security Cryptography Privacy
Por Development Team •

AES Cipher

A professional-grade encryption tool featuring dual-mode operation: Password-based encryption with PBKDF2 key derivation, and Manual Key/IV mode for direct cryptographic control. Supports both AES-GCM (authenticated) and AES-CBC (classic) modes with flexible key sizes (128/192/256-bit). Compatible with .NET and other platforms. All processing happens locally in your browser - your data and passwords never leave your device.

Key Features

Encryption Modes

  • Password Mode (PBKDF2) → Secure password-based encryption with automatic key derivation
  • Manual Key & IV Mode → Direct control with hexadecimal or UTF-8 encoded keys
  • AES-GCM → Authenticated encryption with built-in integrity verification
  • AES-CBC → Classic mode compatible with most systems and .NET applications

Key Sizes & Flexibility

  • AES-128 → 16-byte keys (fast, secure for most uses)
  • AES-192 → 24-byte keys (balanced security)
  • AES-256 → 32-byte keys (maximum security, NSA TOP SECRET approved)
  • Hexadecimal Encoding → Standard format for keys and IVs
  • UTF-8 Encoding → .NET Encoding.UTF8.GetBytes() compatible mode

Security Features

  • 100% Client-Side → All encryption happens in your browser
  • No Server Communication → Your data never leaves your device
  • Web Crypto API → Native browser cryptography
  • Configurable Iterations → Adjust security vs. speed (10K-1M iterations)
  • Strong Password Generation → Built-in secure password generator
  • Format Support → Base64 and Hexadecimal output formats

Functionality

  • Real-time encryption and decryption
  • Automatic format detection (Base64/Hex)
  • Password visibility toggle
  • Secure random password generator (32 characters)
  • Advanced options for PBKDF2 iterations
  • Output format selection (Base64/Hex)
  • Copy to clipboard functionality
  • Download encrypted/decrypted files
  • Paste from clipboard support
  • Execution time tracking
  • Visual success/error feedback

How to Use

Encrypt Mode

Password-Based Encryption (Default)

  1. Switch to the “Encrypt” tab (default)
  2. Enter or paste your plain text in the input area
  3. Enter a strong password (or click “Generate” for a secure random password)
  4. Click “Encrypt”
  5. Copy the encrypted output or download it as a file

Important: Save your password securely! Without it, you cannot decrypt your data.

Manual Key & IV Encryption (Advanced)

  1. Enter your plain text
  2. Click “Advanced Options”
  3. Select “Manual Key & IV” as encryption mode
  4. Select cipher algorithm:
    • AES-GCM: Authenticated encryption (recommended)
    • AES-CBC: Classic mode (.NET compatible)
  5. Select encoding:
    • Hexadecimal: Standard format
    • UTF-8 String: For .NET Encoding.UTF8.GetBytes() compatibility
  6. Select key size: AES-128, AES-192, or AES-256
  7. Enter your key and IV (or click “Generate” for each)
  8. Click “Encrypt”
  9. Save the key, IV, and encrypted text separately

Advanced Options

  • PBKDF2 Iterations (Password mode):
    • 100,000 (default): Good balance of security and speed
    • 500,000: Higher security, slower
    • 1,000,000: Maximum security, slowest
  • Output Format:
    • Base64: Compact, standard format
    • Hexadecimal: Longer but readable

Decrypt Mode

Password-Based Decryption

  1. Switch to the “Decrypt” tab
  2. Paste your encrypted text
  3. The format will be auto-detected (Base64 or Hex)
  4. Enter the same password used for encryption
  5. Click “Decrypt”
  6. View the decrypted text with visual confirmation (green checkmark)

Manual Key & IV Decryption

  1. Switch to the “Decrypt” tab
  2. Paste your encrypted text
  3. Click “Advanced Options”
  4. Select “Manual Key & IV” as decryption mode
  5. Select the same cipher algorithm used for encryption (AES-GCM or AES-CBC)
  6. Select the same encoding used for encryption (Hex or UTF-8)
  7. Select the same key size used for encryption
  8. Enter the exact same key and IV used for encryption
  9. Click “Decrypt”
  10. View the decrypted text

.NET Compatibility Mode

For decrypting data encrypted with .NET Encoding.UTF8.GetBytes():

  1. Select “UTF-8 String (.NET style)” as encoding
  2. Select “AES-CBC” as cipher algorithm
  3. Enter the key and IV strings (not hex)
  4. The key length determines AES variant automatically

Troubleshooting Decryption

If decryption fails:

  • ✗ Wrong password/key: Verify exact password or key/IV values
  • ✗ Corrupted data: Ensure the encrypted text is complete and unmodified
  • ✗ Format mismatch: Verify Base64 or Hexadecimal format
  • ✗ Cipher mode mismatch: Must use same mode (GCM/CBC) as encryption
  • ✗ Encoding mismatch: Hex vs UTF-8 must match encryption
  • ✗ Key size mismatch: AES-128/192/256 must match encryption

Use Cases

  • Secure Communication: Encrypt messages before sending via email or chat
  • Password Storage: Encrypt sensitive passwords and keys
  • Data Protection: Protect confidential documents and notes
  • File Encryption: Encrypt text files before cloud storage
  • Secure Backups: Create encrypted backups of important data
  • Cross-Platform Integration: Decrypt data from .NET, Java, Python applications
  • API Security: Encrypt/decrypt data for secure API communication
  • Development: Encrypt configuration files and secrets
  • Compliance: Meet data protection regulations (GDPR, HIPAA)
  • Legacy Systems: Compatible with AES-CBC implementations
  • Testing: Test encryption implementations across platforms

Technical Specifications

Encryption Process (Password Mode)

  1. Password → Key Derivation: PBKDF2-SHA256 with random 16-byte salt
  2. Random IV Generation: 12 bytes (GCM) or 16 bytes (CBC)
  3. AES Encryption: GCM (authenticated) or CBC (classic) mode
  4. Output Packaging: Iterations(4) + Salt(16) + IV(12/16) + Ciphertext
  5. Encoding: Base64 or Hexadecimal encoding for storage/transmission

Encryption Process (Manual Key/IV Mode)

  1. Key Input: User provides key in hex or UTF-8 format (16/24/32 bytes)
  2. IV Input: User provides IV in hex or UTF-8 format (12/16 bytes)
  3. Key Import: Import raw key bytes with selected AES variant
  4. AES Encryption: Direct encryption with GCM or CBC mode
  5. Output: Base64 or Hexadecimal encoded ciphertext only

Decryption Process (Password Mode)

  1. Input Parsing: Extract iterations, salt, IV, and ciphertext
  2. Key Re-derivation: PBKDF2 with same salt and iterations
  3. AES Decryption: GCM (with authentication) or CBC mode
  4. Verification: GCM tag validates integrity, CBC verifies padding
  5. Output: Original plaintext

Decryption Process (Manual Key/IV Mode)

  1. Input: User provides ciphertext, key, and IV (same format as encryption)
  2. Key Import: Import raw key bytes with matching AES variant
  3. AES Decryption: Direct decryption with same cipher mode used for encryption
  4. Verification: GCM authentication or CBC padding validation
  5. Output: Original plaintext

Security Notes

  • AES-256 is approved by NSA for TOP SECRET information
  • GCM mode provides authenticated encryption (AEAD)
  • PBKDF2 with 100,000+ iterations resists brute-force attacks
  • Random salt prevents pre-computed rainbow table attacks
  • Random IV ensures unique ciphertext for identical plaintext
  • Web Crypto API uses hardware acceleration when available

Performance

  • Encryption: Typically 5-50ms depending on iterations and text length
  • Decryption: Similar to encryption time
  • Iterations impact: 100K iterations ≈ 10-20ms, 1M iterations ≈ 100-200ms
  • Browser optimized: Uses SubtleCrypto for native performance

Best Practices

  1. Password Strength: Use at least 16 characters with mixed case, numbers, and symbols
  2. Password Storage: Use a password manager or secure storage
  3. Backup: Save encrypted text and password separately
  4. Iterations: Use 100,000+ for general use, 500,000+ for sensitive data
  5. Format: Base64 for storage, either format works for transmission
  6. Testing: Test decryption immediately after encryption
  7. Never: Share passwords via the same channel as encrypted data

Compatibility

  • Modern Browsers: Chrome, Firefox, Safari, Edge (all recent versions)
  • Web Crypto API: Required (available in all modern browsers)
  • Mobile: Fully functional on iOS and Android browsers
  • Cross-Platform: Encrypt on one device, decrypt on another
  • Standards-Based: Uses IETF and NIST approved algorithms

Security Guarantee: All cryptographic operations use the browser’s native Web Crypto API, which implements industry-standard algorithms. No custom crypto implementations are used.

Privacy Guarantee: Zero data transmission - everything happens locally. Your plaintext, ciphertext, and passwords never leave your browser.